Early development of human gastric H,K-adenosine triphosphatase

Background: Little is known about the early development of the gastric acid secretion in human neonates. The purpose of this study was to examine the early development of gastric H,K-adenosine triphosphatase (ATPase) by analy zing human gastric biopsy specimens. Methods: Eighty-eight neonates from week 25 to week 42 of gestation who wer e treated in a neonatal intensive care unit underwent gastroscopy with biop sy specimens obtained from the corpus. The expression of gastric H,K-ATPase protein in the gastric biopsy specimens was assessed by Western blot analy sis, using an antibody directed against the gastric H,K-ATPase. The amount of H,K-ATPase expressed was compared with age, gender, clinical factors, di seases, and the macroscopic and histologic findings at endoscopy. Results: The expression of human gastric H,K-ATPase increased significantly with gestational age. There was a significant increase in the expression o f gastric H,K-ATPase during the first 82 days after birth. Boys had a signi ficantly higher expression of gastric H,K-ATPase than girls did, when it wa s adjusted for gestational and postnatal age. Neither the clinical features nor treatments showed significant correlations with the expression of huma n gastric H,K-ATPase when controlling for gestational and postnatal age. Conclusions: This study shows that human gastric H,K-ATPase is expressed fr om week 25 of gestation, which agrees with earlier findings of gastric pH i n preterm infants. The amount of enzyme expressed increases with gestationa l and postnatal age. The authors speculate that the susceptibility to gastr ic lesions seen in neonates is not related to the amount of H,K-ATPase. How ever, studies elucidating the ontogeny of gastric mucosal defense mechanism s are warranted. (C) 2000 Lippincott Williams & Wilkins, Inc.